Proefschrift: Bestraling hypofysetumor

door | mei 27, 2015 | Geen categorie

Op 27 mei jl is drs. G.A. (Margriet) Sattler gepromoveerd op het proefschrift: “The long-term side effects of postoperative radiation therapy in pituitary adenoma patients”

Voor meer gedetailleerde informatie, zie http://www.rug.nl/news-and-events/events/phd-ceremonies/?hfId=118185

Samenvatting van haar proefschrift / summary of her thesis:

“External beam radiation therapy radiation therapy in pituitary adenoma results in excellent local tumour control rates and improvements in excessive hormonal secretion. However, the safety of postoperative radiation therapy has been questioned in particular because of concerns related to possible long-term radiation-induced side effects, although serious late complications of radiation therapy are uncommon in pituitary adenoma patients. However, these concerns are often used to delay or reject radiation therapy.

The main aim of this thesis was to assess and compare several long-term side effects of conventional radiation therapy (i.e. incidence of second tumours, stroke, mortality, and radiological brain abnormalities, effects on cognition, and sexual function as aspect of quality of life) in pituitary adenoma patients treated with surgery and postoperative radiation therapy versus surgery alone and with a population without pituitary adenoma disease (i.e. the reference population).

None of our observational studies shows significant differences in long-term side-effects between pituitary adenoma patients treated with radiation therapy and surgery alone. However, the decision to treat with postoperative radiation therapy is based on a careful assessment of the balance of benefits and risks in the individual pituitary adenoma patient. The risk of serious radiation-induced long-term side effects is low with the radiation therapy techniques applied in the last decades and is expected to be lower with modern and more advanced radiation therapy techniques. Therefore, in most pituitary adenoma patients with otherwise uncontrolled disease, the benefits of postoperative radiation therapy outweighs the absolute small risk of serious side-effects.”

 

Proefschrift: Vascular progenitor cells

door | okt 2, 2013 | Geen categorie

On October 2, 2013, Joris van Ark, defended his thesis titled:

Role of circulating vascular progenitor cells in the development of macrovascular disease in diabetes.

Promotores were Prof. dr. J.L. Hillebrand and Prof. dr. B.H.R. Wolffenbuttel.

 

Joris  studied the role of vascular progenitor cells in diabetes. Cardiovascular diseases are the number one cause of death in industrialised countries. Macrovascular disease (MVD) contributes to this to a considerable extent. Type 2 diabetes is associated with a 2- to 4-fold increase in rates of MVD. The underlying causes of the accelerated progression of MVD in diabetes are incompletely understood. Therefore, new insights into the mechanisms behind the development of MVD are essential to develop effective therapies for the prevention and treatment of MVD in patients with diabetes. Circulating vascular progenitor cells (VPCs) contribute to the health and maintenance of blood vessels. Different types of VPCs are described which have different effects on the development of MVD. Endothelial progenitor cells (EPCs) and circulating angiogenic cells (CACs) inhibit the progression of MVD. On the other hand, smooth muscle progenitor cells (SMPCs) are able to stimulate the progression of MVD. In this thesis we investigated the role of circulating VPCs in the development of MVD in patients with type 2 diabetes. We demonstrate that the number of protective EPCs and CACs is decreased in the blood of diabetic patients. In contrast, the number of damaging SMPCs is slightly increased in these patients. Therefore, the balance between protective and damaging VPCs is disturbed in favour of the latter. This may contribute to the accelerated development of MVD in patients with diabetes. This makes VPCs a potential therapeutic target to inhibit the progression and prevent the complications of MVD in patients with type 2 diabetes.